[PATCH net] mdio: mux: fix parsing mux registers outside of the PHY address range

[Neil Armstrong]

On 07/10/2017 02:35 PM, Martin Blumenstingl wrote:
> mdio_mux_init parses the child nodes of the MDIO mux. When using
> "mdio-mux-mmioreg" the child nodes are describing the register value
> that is written to switch between the MDIO busses.
> 
> The change which makes the error messages more verbose changed the
> parsing of the "reg" property from a simple of_property_read_u32 call
> to of_mdio_parse_addr. On a Khadas VIM (based on the Meson GXL SoC,
> which uses mdio-mux-mmioreg) this prevents registering the MDIO mux
> (because the "reg" values on the MDIO mux child nodes are 0x2009087f
> and 0xe40908ff) and leads to the following errors:
>   mdio-mux-mmioreg c883455c.eth-phy-mux: /soc/periphs at c8834000/eth-phy-mux/mdio at e40908ff PHY address -469169921 is too large
>   mdio-mux-mmioreg c883455c.eth-phy-mux: Error: Failed to find reg for child /soc/periphs at c8834000/eth-phy-mux/mdio at e40908ff
>   mdio-mux-mmioreg c883455c.eth-phy-mux: /soc/periphs at c8834000/eth-phy-mux/mdio at 2009087f PHY address 537462911 is too large
>   mdio-mux-mmioreg c883455c.eth-phy-mux: Error: Failed to find reg for child /soc/periphs at c8834000/eth-phy-mux/mdio at 2009087f
>   mdio-mux-mmioreg c883455c.eth-phy-mux: Error: No acceptable child buses found
>   mdio-mux-mmioreg c883455c.eth-phy-mux: failed to register mdio-mux bus /soc/periphs at c8834000/eth-phy-mux
> (as a result of that ethernet is not working, because the PHY which is
> connected through the mux' child MDIO bus, which is not being
> registered).
> 
> Fix this by reverting the change from of_mdio_parse_addr to
> of_mdio_parse_addr.
> 
> Fixes: 342fa1964439 ("mdio: mux: make child bus walking more permissive and errors more verbose")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> ---
>  drivers/net/phy/mdio-mux.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
> index 00755b6a42cf..c608e1dfaf09 100644
> --- a/drivers/net/phy/mdio-mux.c
> +++ b/drivers/net/phy/mdio-mux.c
> @@ -135,8 +135,8 @@ int mdio_mux_init(struct device *dev,
>  	for_each_available_child_of_node(dev->of_node, child_bus_node) {
>  		int v;
>  
> -		v = of_mdio_parse_addr(dev, child_bus_node);
> -		if (v < 0) {
> +		r = of_property_read_u32(child_bus_node, "reg", &v);
> +		if (r) {
>  			dev_err(dev,
>  				"Error: Failed to find reg for child %s\n",
>  				of_node_full_name(child_bus_node));
> 

I was going to push this, thanks martin !!

Acked-by: Neil Armstrong <narmstrong at baylibre.com>

Neil